TTR and open-angle glaucoma: Specifically, in a first stage, SELDI-TOF-MS was conducted on 22 POAG and 24 control samples, while 2D electrophoresis was applied to 33 POAG and 31 control subjects, identifying by means of LC–MS/MS the upregulation of TTR (1.9-fold), further confirmed in a second stage by ELISA.